-LRB- CNN -RRB- -- Formal charges are expected against seven Royal Marines who were arrested this week on suspicion of murder involving an incident in Afghanistan in 2011 , a British Ministry of Defense spokesman said .

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The arrests were made after an incident in Helmand province , the spokesman said .

All seven are in the UK and will proceed through a military court system that mirrors the civilian legal system .

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The incident occurred after an engagement with an insurgent , and no civilians were involved , the spokesman said .

Those arrested were part of Operation Herrick 14 , as Britain 's efforts in Afghanistan are known . The operation they were carrying out at the time did not involve any special forces , the spokesman said .

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`` The investigation will now be taken forward and dealt with by the Service Justice system , '' the spokesman said . `` These arrests demonstrate the Department and the Armed Forces ' determination to ensure UK personnel act in accordance with their Rules of Engagement and our standards . ''

The military will review the serious incident to identify lessons learned , the spokesman said .

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Seven Royal Marines are under arrest on suspicion of murder

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The charges involve an incident in Afghanistan 's Helmand province in 2011

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No civilians were involved with the incident , British Ministry of Defense spokesman says